办公建筑高效制冷机房研究与实践

公共建筑空调系统能耗占建筑运行总能耗的40%~60%,研究并推广高效制冷机房技术是建筑行业实现“双碳”战略的有效手段。目前国内外技术标准及工程案例更多关注的是高效制冷机房整体能效比(EER),对高效制冷机房EER的影响因素及提升技术策略研究较少。本文结合理论及工程案例,研究明确了高效制冷机房EER的影响因素及其相互关系,提出了包含冷水机组选型优化适配、能源梯级利用、输配系统优化、精细化监测与控制等技术策略,并详细介绍了中国海外大厦项目应用实例,旨在为同类项目提供参考,助力高效制冷机房技术在办公建筑中产业化应用。

日本《街道设计导则》解读及对中国的启示

中国的街道设计工作正在从早期重视单一的交通功能向交通功能与空间场所功能并重的阶段转型。日本拥有与中国相近的文化特征,在《街道设计导则》(以下简称《导则》)编制以及相关工程实践领域取得了显著成就,对中国有一定借鉴价值。首先,回顾日本街道设计的发展历程和《导则》的编制背景。然后,梳理日本相较于其他国家或城市独特的《导则》编制目的、研究范围及内容框架。同时,从街道设计的构成要素、交通环境建设与管理措施、制度设计等方面对《导则》核心内容展开解读。最后,基于日本的成功经验进一步反思街道设计工作的原则与初衷,提出对中国编制、修订街道设计导则以及项目实践的启示。

Interferon-γpriming enhances the therapeutic effects of menstrual blood-derived stromal cells in a mouse liver ischemia-reperfusion model

BACKGROUND Mesenchymal stem cells(MSCs)have been used in liver transplantation and have certain effects in alleviating liver ischemia-reperfusion injury(IRI)and regulating immune rejection.However,some studies have indicated that the effects of MSCs are not very significant.Therefore,approaches that enable MSCs to exert significant and stable therapeutic effects are worth further study.AIM To enhance the therapeutic potential of human menstrual blood-derived stromal cells(MenSCs)in the mouse liver ischemia-reperfusion(I/R)model via interferon-γ(IFN-γ)priming.METHODS Apoptosis was analyzed by flow cytometry to evaluate the safety of IFN-γpriming,and indoleamine 2,3-dioxygenase(IDO)levels were measured by quantitative real-time reverse transcription polymerase chain reaction,western blotting,and ELISA to evaluate the efficacy of IFN-γpriming.In vivo,the liver I/R model was established in male C57/BL mice,hematoxylin and eosin and TUNEL staining was performed and serum liver enzyme levels were measured to assess the degree of liver injury,and regulatory T cell(Treg)numbers in spleens were determined by flow cytometry to assess immune tolerance potential.Metabolomics analysis was conducted to elucidate the potential mechanism underlying the regulatory effects of primed MenSCs.In vitro,we established a hypoxia/reoxygenation(H/R)model and analyzed apoptosis by flow cytometry to investigate the mechanism through which primed MenSCs inhibit apoptosis.Transmission electron microscopy,western blotting,and immunofluorescence were used to analyze autophagy levels.RESULTS IFN-γ-primed MenSCs secreted higher levels of IDO,attenuated liver injury,and increased Treg numbers in the mouse spleens to greater degrees than untreated MenSCs.Metabolomics and autophagy analyses proved that primed MenSCs more strongly induced autophagy in the mouse livers.In the H/R model,autophagy inhibitors increased the level of H/R-induced apoptosis,indicating that autophagy exerted protective effects.In addition,primed MenSCs decreased the level of H/R-induced apoptosis via IDO and autophagy.Further rescue experiments proved that IDO enhanced the protective autophagy by inhibiting the mammalian target of rapamycin(mTOR)pathway and activating the AMPK pathway.CONCLUSION IFN-γ-primed MenSCs exerted better therapeutic effects in the liver I/R model by secreting higher IDO levels.MenSCs and IDO activated the AMPK-mTOR-autophagy axis to reduce IRI,and IDO increased Treg numbers in the spleen and enhanced the MenSC-mediated induction of immune tolerance.Our study suggests that IFN-γ-primed MenSCs may be a novel and superior MSC product for liver transplantation in the future.

叶轮不同叶片对离心泵内流道流场的影响

对离心泵进行三维建模,并对内部流场进行数值模拟.采用"仿真-实验"法验证了六叶片离心泵流场仿真的合理性,研究了叶轮上不同叶片数对内流道流场的影响.数值模拟原理为大涡模拟,通过网格直接模拟大尺度的紊流运动,同时,利用次网格尺度模型来模拟小尺度紊流运动对大尺度紊流运动所造成的影响.大涡模拟可以获得雷诺时均模拟法无法获得的流场细微图像.模拟结果表明:离心泵叶片数量过多,会使叶片表面摩擦力做功加大,使得离心泵出口处的总功减少,从而降低离心泵的扬程和效率.经过模拟实验研究分析发现,当叶片数为5时,离心泵流场的综合性能最好,运行效率最高,湍流强度低,流场稳定性最好.

Role of upper endoscopy in diagnosing opportunistic infections in human immunodeficiency virus-infected patients

Highly active antiretroviral therapy (HAART) has dramatically decreased opportunistic infections (OIs) in human immunodef iciency virus (HIV)-infected patients. However,gastrointestinal disease continues to account for a high proportion of presenting symptoms in these patients. Gastrointestinal symptoms in treated patients who respond to therapy are more likely to the result of drug-induced complications than OI. Endoscopic evaluation of the gastrointestinal tract remains a cornerstone of diagnosis,especially in patients with advanced immunodeficiency,who are at risk for OI. The peripheral blood CD4 lymphocyte count helps to predict the risk of an OI,with the highest risk seen in HIV-infected patients with low CD4 count (< 200 cells/mm3). This review provides an update of the role of endoscopy in diagnosing OI in the upper gastrointestinal tract in HIV-infected patients in the era of HAART.

超长GIL管廊排热通风研究

武汉谭鑫培路地下综合管廊GIL舱属于超长封闭的构筑物,排热通风问题成为该工程设计的控制性问题,特别是舱体与周围土体的传热问题。基于IDA隧道模拟软件建立GIL舱一维分析模型,对当前通风系统在夏季、冬季与过渡季节典型气候下的短期排热,以及1年、10年和30年考虑季节变化下的长期排热进行分析。短期分析结果表明,管廊坡度和温度梯度会降低某些区域的目标通风率,在设计中应引起重视。长期分析结果表明,舱内空气和壁面温度升高在运行的前5、6年最为显著,并在30年的剩余时间内保持稳定,舱壁与周围土体释放10%～40%的热量。基于计算流体力学软件OpenFOAM建立GIL舱三维节段模型,分析电缆和支架对舱内温度场与速度场的影响,揭示GIL舱内速度分布的不均匀性与烟囱效应对温度分布的影响。

A new species of the genus Theloderma Tschudi, 1838 (Amphibia： Anura： Rhacophoridae) from Tay Nguyen Plateau, central Vietnam

A new species of small tree frog from a primary montane tropical forest of central Vietnam, Tay Nguyen Plateau, is described based on morphological, molecular, and acoustic evidence. The Golden Bug-Eyed Frog, Theloderma auratum sp. nov., is distinguishable from its congeners and other small rhacophorid species based on a combination of the following morphological attributes： （1） bony ridges on head absent; （2） smooth skin completely lacking calcified warts or asperities; （3） pointed elongated tapering snout; （4） vocal opening in males absent; （5） vomerine teeth absent; （6） males of small body size （SVL 21.8-26.4 mm）; （7） head longer than wide; ED/SVL ratio 13%-15%; ESL/SVL ratio 16%-20%; （8） small tympanum （TD/EL ratio 50%-60%） with few tiny tubercles; （9） supratympanic fold absent; （10） ventral surfaces completely smooth; （11 ） webbing between fingers absent; （12） outer and inner metacarpal tubercles present, supernumerary metacarpal tubercle single, medial, oval in shape; （13） toes half-webbed： I 2-21/4 II 11/^-23/~ III 2-31/4 IV 3-11/2 V; （14） inner metatarsal tubercle present, oval; outer metatarsal tubercle absent; （15） iris bicolored; （16） dorsal surfaces golden-yellow with sparse golden-orange speckling or reticulations and few small dark-brown spots; （17） lateral sides of head and body with wide dark reddish-brown to black lateral stripes, clearlyseparated from lighter dorsal coloration by straight contrasting edge; （18） ventral surfaces of body, throat, and chest greyish-blue with indistinct brown confluent blotches; （19） upper eyelids with few （3-5） very small flat reddish superciliary tubercles; （20） limbs dorsally reddish-brown, ventrally brown with small bluish-white speckles. The new species is also distinct from all congeners in 12S rRNA to 16S rRNA mitochondrial DNA fragment sequences （uncorrected genetic distance P〉8.9%）. Advertisement call and tadpole morphology of the new species are described. Our molecular data showed Theloderma auratum sp. nov. to be a sister species of Th. palliatum from Langbian Plateau in southern Vietnam.

基于GSRaft的高层建筑沉降后浇带的有效性分析

主群之间设置的沉降后浇带可有效释放主裙楼地基间的差异沉降,避免次生内力对结构不利影响。但沉降后浇带的设置的具体位置直接影响差异沉降解决的效果。本文介绍了GSRaft计算分析特点及原理,并通过具体工程案例的结构——桩筏基础——土体的协同变形分析,对沉降后浇带不同设置位置的筏板变形特征进行定量分析。结果显示,相比后浇带设置于主楼外第二跨的情况,当后浇带设置在主楼外第一跨时,主楼最大沉降虽有少量增加,但可明显提高后浇带对主裙差异沉降的释放效果。此外,本文还对提高浇带有效性的其他措施进行讨论。

Dynamic Optimization of a 2-DOF Pseudo-Equatorial Tracking System

The key word for the design process of the photovoltaic tracking systems is the energetic efficiency. Using the tracking system, the photovoltaic panel follows the sun and increases the collected energy, but the driving motors consume a part of this energy. In these terms, the optimization of the tracking systems became an important challenge in the modem research and technology. In this paper, a strategy for the dynamic optimization of the photovoltaic tracking systems is presented. The main task in optimization is to maximize the energetic gain by increasing the incoming solar radiation and minimizing the energy consumption for tracking. This strategy is possible by developing the virtual prototype of the tracking system, which is a control loop composed by the multi-body mechanical model connected with the dynamic model of the actuators and with the controller model. In this way, it is possible to optimize the tracking mechanism, choose the appropriate actuators, and design the optimal controller.

光纤地波周界安防设备设计与实现

为了增强对地下文物的安全保护,设计了一种智能光纤地波周界安防设备。通过将马赫-曾德尔光纤干涉技术应用于地波传感器,实现对地波微震动的监听。利用软件算法分析微震动波的幅频特性值,智能过滤干扰,对入侵行为进行甄别、记录和报警联动。实验结果表明,该设备单探点有效监控范围在半径25m内,单系统最大探点数量为64个,预警辨别时间小于2s。

基于室内无线模型的穿墙损耗校正

K-M(Keenan-Motley)模型将单墙固定损耗值相加来计算室内无线信号穿透多墙的总损耗值,存在较大误差。针对该问题选取多种室内场景分别进行连续波(Continuous Wave,CW)测试,对无线信号穿墙损耗的影响因素和变化规律进行分析,提出了一种基于人工神经网络的室内无线模型穿墙损耗校正方法,对预处理后的测试数据进行训练并建立预测模型。经验证该预测模型符合校正判别准则,在实际场景下具有良好的预测准确度。

管线敷设与风机室布置对综合管廊通风阻力影响研究

为准确估算管线敷设与风机室内气流相互作用对压降损失的影响,基于武汉市江夏区谭鑫培路地下综合管廊项目建立典型数值分析模型与分析流程。通过建立典型管线布置的GIL舱、高压舱与综合舱的计算流体动力学三维模型,分别对入口段与稳定段进行分析,并使用循环边界条件来考虑稳定段流体的充分发展,得到阻力系数随流量的变化规律;通过建立GIL舱典型排风口三维模型,分析风机室中不同风机的压降损失,并与规范估算值进行比较。研究结果表明:管线敷设对压降损失的影响不可忽视;风机室风机相互作用显著,规范不能准确估算该相互作用导致的压降损失。

超长GIL综合管廊SF6气体泄露模拟研究

GIL导线中充满SF6气体,由于制造、运输、安装与老化等原因,综合管廊GIL舱存在SF6气体事故泄露的可能性,故应设置专门的监测控制系统与排风系统。文章以武汉谭鑫培路地下综合管廊6.3 km超长GIL舱为案例,结合GIL舱排热通风数据与SF6气体扩散特性,确定管廊发生气体泄漏后最不利的泄露位置与工况。通过开源计算流体动力学软件OpenFOAM,建立了SF6气体扩散的三维长节段模型与详细短节段模型,并且给出了数值分析流程。在SF6气体典型事故工况中,以排热通风分析的数据作为边界条件进行了分析,从而得到在既有排热通风系统下GIL舱内SF6气体浓度场的变化趋势。分析结果表明,SF6气体主要由常规排热通风系统排出,但是辅助系统能够很大程度上节省排风时间,相关数据可为通风系统与监测系统的优化设计提供建议。数值模拟方法可为其它类型重气在管廊内泄露扩散模拟提供参考。

某两江交汇处来流风场的地形试验研究

风场模型是高层建筑结构设计的基本参数,特别是平均风速剖面与湍流强度剖面。风场模型取值是否合理对项目的安全性与经济性有很大影响。对于受地形效应影响显著的场地,一般借助大气边界层风洞试验或数值模拟来得到项目所在地的远场风场模型。以实际复杂地形下的风洞试验为例,介绍了1∶3000缩尺比地形试验的全过程,重点对不同风向角下的平均风速剖面与湍流强度剖面进行了研究,并采用非线性最小二乘法拟合不同风向角下的平均风速剖面与湍流强度剖面指数率经验公式。试验结果表明,复杂地形显著增大地面粗糙度,实际风场与荷载规范的平坦地貌风场存在很大不同,基于风洞试验结果可以减小荷载规范风场中不必要的保守性。采用的试验方法以及风场模型经验公式,可为类似复杂地形项目提供参考价值。

Highly active PtAu alloy surface towards selective formic acid electrooxidation

The electrochemical oxidation of formic acid has been attracting significant attention in the past few years due to the great potential prospect of direct formic acid fuel cell (DFAFC) in applications, including high theoretical open circuit potential (1.48 V), low fuel crossover, high practical power densities at low temperature, facilitating of proton transport in catalyst layers and low toxicity [1-5].

Optical clearing mechanisms characterization in muscle

Optical immersion clearing is a technique that has been widely studied for more than two decades and that is used to originate a temporary transparency effect in biological tissues.If applied in cooperation with clinical methods it provides optimization of diagnosis and treatment procedures.This technique turns biological tissues more transparent through two main mechanisms-tissue dehydration and refractive index(RI)matching between tissue compo-nents.Such matching is obtained by partial replacement of interstit ial water by a biocompat ible agent that presents higher RI and it can be completely rever sible by natural rehydration in vrivo or by assisted rehydration in ex vivo tissues.Experimental data to characterize and discriminate between the two mechanisms and to find new ones are necessary.Using a simple method,based on collimated transmittance and thickness measurements made from muscle samples under treatment,we have estimated the diffusion properties of glucose,ethylene glycol(EG)and water that were used to perform such char acterization and discrimination.Comparing these properties with data from literature that characterize their diffusion in water we have observed that musde cell membrane permeability limits agent and water diffusion in the muscle.The same experi-mental data has allowed to calculate the optical dearing(OC)eficiency and make an inter-pretation of the internal changes that occurred in muscle during the treatments.The same methodology can now be used to perform similar studies with other agents and in other tissues in order to solve engineering problems at design of inexpensive and robust technologies for a consider.able improvement of optical tomogr aphic techmiques with better contrast and in depth imaging.

Default or profit scoring credit systems?Evidence from European and US peer-to-peer lending markets

For the emerging peer-to-peer(P2P)lending markets to survive,they need to employ credit-risk management practices such that an investor base is profitable in the long run.Traditionally,credit-risk management relies on credit scoring that predicts loans’probability of default.In this paper,we use a profit scoring approach that is based on modeling the annualized adjusted internal rate of returns of loans.To validate our profit scoring models with traditional credit scoring models,we use data from a European P2P lending market,Bondora,and also a random sample of loans from the Lending Club P2P lending market.We compare the out-of-sample accuracy and profitability of the credit and profit scoring models within several classes of statistical and machine learning models including the following:logistic and linear regression,lasso,ridge,elastic net,random forest,and neural networks.We found that our approach outperforms standard credit scoring models for Lending Club and Bondora loans.More specifically,as opposed to credit scoring models,returns across all loans are 24.0%(Bondora)and 15.5%(Lending Club)higher,whereas accuracy is 6.7%(Bondora)and 3.1%(Lending Club)higher for the proposed profit scoring models.Moreover,our results are not driven by manual selection as profit scoring models suggest investing in more loans.Finally,even if we consider data sampling bias,we found that the set of superior models consists almost exclusively of profit scoring models.Thus,our results contribute to the literature by suggesting a paradigm shift in modeling credit-risk in the P2P market to prefer profit as opposed to credit-risk scoring models.

Reproductive Parameters and Characteristics of Labrador Breed

For a period of two years, a survey of 110 parturitions of Labrador breed bitches was carried out in Rosario City to determine the average number of puppies per litter, percentage of dystocia of all parturitions, percentage of males and females born and causes of dystocia, as well as the incidence of clinically detectable congenital pathologies. Over a total of 110 parturitions ninety three （84.5%） parturitions were normal and 17 （15.5%） were dystocic ones, it was established that atony 1 was the most numerous cause of dystocia （53%）, followed by atony 2 （23%）, dystocia by fetal disorders （6%）, hydramnios （6%）, uterine rupture （6%） and vagina fibrous band （6%）. The whole puppies born was 866, 7.9 puppies per litter, if comparison between normal parturitions and dystocic ones is made, numbers are 7.05 and 8.02 respectively. When sex evaluation percentage is made 51.5% are males and 48.5% are females. When viability of puppies born is calculated it is established that in ones born by normal parturition perinatal death was 9.3%, while in those born by dystocia it was 10.9%. Among clinically verifiable congenital disorders low weight at birth was the most frequent congenital alteration, followed by cleft palate, lethal congenital edema or walrus syndrome and hare lip.

工业革命4.0给科技伦理带来的风险与挑战

2010年以来,以信息化、智能化、物理、数字和生物等领域新技术融合为标志的工业革命4.0,给社会生产生活带来巨大变化和新的机遇,同时,也使人类陷入前所未有的新的伦理困境。工业革命4.0有其深刻的历史根源,西方主要学术流派对工业革命4.0带来的科技伦理风险进行了反思,并提出了有代表性的观点。在此基础上,系统梳理了全球化时代工业革命4.0的科技进步带来的伦理挑战,探讨了新时代科技与工程教育的新视角、新观点与新方法。